A billabong is essentially a large pond or creek that at one time extended from a river. A billabong is the cut off extension of a river that changed its course over time. During a wet season, the billabong often connects back with the river, receiving fresh water, at least until the area dries back up.
Billabong is an Australian term, derived from the Wiradjuri language that is indigenous to new South Wales. Many billabongs are found after Australia's wet season has concluded. They can also form after intense flooding in an area. A billabong can also be referred to as an oxbow lake.